1. Technical Field
The present invention relates to a display control apparatus including a display unit with a touch panel.
2. Description of the Related Art
In recent years, a display control apparatus including a display unit with a touch panel having a sensor on a display so as to accept input through a touch operation on a screen of the display with a finger or a special pen is known. Since such a display control apparatus allows input operations by directly touching the screen, a direct and intuitive operation may be performed while visually identifying the screen.
Various types of touch panels included in display units with a touch panel are known. One type of the touch panel includes a capacitance touch switch using a capacitance sensor. The switch detects operational input while changing detection sensitivity from a high to low level. A touch operation may be reliably detected even when a thick glove is worn or when a finger is not covered by a glove.
The known display control apparatus including a display unit with a touch panel may intends to reliably detect a touch operation to a touch panel on the assumption that an installation location of a display unit with the touch panel in a display control apparatus is fixed. Specifically, sensitivity of a capacitance sensor is adjusted to compensate for a difference in a capacity change caused by existence of a glove etc. covering a finger reaching to the touch panel or thickness and material of the glove etc. being worn.
However, in a display control apparatus which allows a display unit with a touch panel to be connected to a plurality of locations on the display control apparatus or in different orientations, a direction and an amount of displacement of a contact area and a position of a finger during a touch operation generally differ for each installation location or each orientation of the display unit with the touch panel. For example, when a touch panel standing at an angle to a horizontal surface is operated from above, a contact area of a finger during a touch operation may become smaller than that on a touch panel placed flat on the horizontal surface. Moreover, when the touch panel is placed at a location higher or lower than an eye line of an operator, a contact position of the finger during the touch operation may be lower or higher than an intended contact position of the finger.
According to the known display control device, conditions such as a detection region and a detection area to detect the touch operation are fixed regardless of the installation location or the orientation of the touch panel. Therefore, the difference in the contact area of the finger or the displacement of the contact position during such a touch operation may cause a problem of not being able to reliably detect a touch operation on the display control apparatus which allows the display unit with a touch panel to be connected to a plurality of locations on the display control apparatus or in different orientations.